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Low Speed Thumping Noise Front Suspension


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Jan 10, 2002
Edmonds, WA
Ugh! ?Seems I have another gremlin in the front end of my Avalanche. ?At very low speeds, under 10 MPH there is a kind of thump/klunk noise. ?It is definitely coming from the front end. ?I can feel the slightest amount of a vibration (not the best way to describe it) in the steering wheel. ?At higher speed (over 10 MPH) the tick in the steering wheel and the sound go away. ?The sound is very similar to the clicking you would here in a front driver with a bad CV joint, but again the sound is only at low speed. The sound does not get less or worse when going straight versus turning versus forward versus backwards - although I hear it a bit less going backwards.

I'm going to take my Av into the dealer but I figured with 3,200+ members I'm not the first one to have this problem SO...what should I tell the dealer to look for so I don't have a repeat of my bad shock situation (three trips to the dealer and two weeks to fix).

As noted below it's a 1500 Z-71 and I'm running in 2-Hi -- haven't tried it in Auto Trac or 4-Hi to see if that makes a difference...
I have a similiar knuckle poping thunk noise at slow speeds also. However, mine is only while turning. Mine is a z66. I'll also be going to the dealer soon.
Could be a multitude of things
Try stepping lightly on the brakes when rolling to eliminate it being a caliper or brake pad rattle
good luck
ME TOO!! :6: It seems to just have appeared this past weekend...or at least this is the first I have heard it. I had a mechanic friend ride with me...he said it is not a CV as they tend to act worse when turing...and as you say that is not the case. It took a few hundred feet before he heard it though....I think it is just because I am used to what my Av 's normal sounds are or are not.
At higher speeds I hear a sound also...kind of an A/C hissing sound...even though all is off...that sound goes away at very low speeds...replaced with the silly putty in a hub cap sound you discribe.

Let me know what your dealer says...mine gets to have mine on the 14th for my heater core buzzing sound (see other thread).

Also Chief- What's up with the very long load time for the site?? With DSL it still is taking over 2 minutes to fully load....but quality is worth waiting for.
Hey Chief and others,

I have had the same problem for quite awhile now.

I notice my thump after the drivetrain is warmed up. After I come to a complete stop, I turn the tires slightly to the right. Then I creep forward very slowly. The thump is rythmic, but more rapid than every revolution of the tire.

I know it is not the brakes, but I cannot determine if its in the front or rear end. They say if you can feel it in the steering wheel, its from the front. If you can feel it in the seat of your pants, its in the rear. But I honestly think its in the front.

I cannot hear the thump, I just feel it. I can feel it in the seat of my pants, and the floorboard. Heck, even passengers in the front and back seats can feel it.

It won't happen every time, and it won't do it at the dealership. There is something definately wrong though.

Keep us informed as I will do the same. I want to eliminate this potential problem.

I had a doctors appointment this morning so I swung by the dealer and had the tech take a listen. It was very obvious to him. They immediately eliminated it as a suspension problem.

The tranny/drive train guy came out and took a listen. He feels it is definitely in the drive train but not 100% sure what it could be. Doesn't think it is the differential or 4WD system as the sound does not get worse or better in Auto Trac or 4WD.

My Av goes in on Monday (Columbus Day) for service so we'll see what they have to say. I've got good vibes they'll find the problem as the noise is very obvious.

On a side note the suspension guy told me that they have had a number of the Z-71's coming in with the bad shock bushing - phooey on Bilstein!!! :7:
funny thing, mine started doing this exact same thing about 2 days ago. I opened the hood, and had my wife drive the truck, recreating the noise.

To me, the sound seemed to emminate from the drive shaft. It was definitely coming from inside the engine compartment, and not from the wheel well. It doesn't mater if I am going straight, or turning, in 4wheel or 2, it is the same noise. And as you said, it only happens between 5-10 mph

Well, I am glad I am not the only one having the problem. Let me know what they find out. Then I can better plan when to take it in.

I had the same problem. It was a worn idle arm :p. And only 19,500 miles on my AV. Once replaced it solved the problem
hey chazmo, do you have a 2wd or 4wd?
chazmo2 said:
I had the same problem. It was a worn idle arm :p. And only 19,500 miles on my AV. Once replaced it solved the problem

Damoncollins & Chief
To answer Damoncollins, I have a 4 WD
Chief that's too coincidental for me. There are alot of post on this subject. Check out my reply to Wiki & cpacowboy. How my dealer said the idle arm was a hard part to get. That's exactly what cpacowboy's service dept. told him. There should be a TSB on this or is it a chevy conspiracy :eek:
Ok well im surrrrrrrrre nobody can beat the problems and noises im havin with my truck. There kinda scary, when going slow there is a loud "TUNK", like loud, thast when turning. I have a rwd z66, and now the differential or something is messed up like one wheel will move and the other will be moving faster than the truck is goin, this is only at like 4 mphs. Its now sittin in my driveway and it will be towed to dealership monday bright and early. Anyone have any idea what the hell is the matter, not to mention the transmission is slipping out of third alot, and since they fixed this problem before, i dont know. I love the truck but its realy beginning to piss me off.
Well this may throw the experiment off a little, but mine is doing it too. ?Only after I lowered it. ?All parts are tight, everything checks out as ok for the suspension. ?I'm afraid to take it to the dealer since they will say, NOT COVERED DUE TO MODIFICATION :( ?I'd like to get lots of evidence from everyone and maybe a TSB before I take it in. ?BTW mine is a 2003 with 800 miles
First off - major kudos to Seaview Chevrolet, Pontiac, GMC, which has redeemed itself after the bad shock fiasco. My Avalanche was fixed on the same day and fixed right.

Now the bad news - the thumping at low speed regardless of whether I was in 4WD or 2WD, and only from 5 MPH to 10 MPH and only under light throttle was caused by a destroyed rear differential. The only part I don't understand is why the noise was coming from the front (as witnessed by two techs).

Still the vehicle is fixed and has a brand new rear-end so I'm thrilled, especially with the fact that it has been fixed right the first go around and no BS. Hope this helps others!
What caused rear end failure chief? Did they have a guess?
ygmn said:
What caused rear end failure chief? ?Did they have a guess?

I am 99% sure that this was directly caused by me being run off the road during Wild West 2002. I had to make a radical manuever in 4-Hi and went into a gully, rocks, etc. After this happened I noticed a whine and commented I was worried I damaged the differential. The whine went away so I figured no problemo - than the thunking started. So I don't blame the Avalanche for this one. Honestly I'm thrilled to have a new rear-end at 19.4K miles - just means it will last all that much longer and I don't have to do the rear end service out of my pocket when the time comes (because I get to wait 20K extra miles). >:D
Just got back from dealer .... "right hub had rust in mounting position ... cleaned and reassembled." is what was on the service ticket ... so far so good.
so, it sounds like any number of things can be causing it. I would hope that with only 9K on my truck, that it wouldn't be anything major. I would hate to think these trucks are fragile. :7:
went to the dealer today for the same clunking noise you all have spoke of. it only seemed to do it at low speeds when turning steering wheel from left to right.
when i picked up the truck this evening it sounded fine. i guess they fixed the problem. could not asked what they did at the time of pickup due to the fact i got there about 1 minute before the service deparment closed.
i will be sure to inquire tomorrow. might just be a simple thing. it has to be since it was there for about four different things, and it was all done in one day.
I just bought a used 2002 AV Z71. My wife noticed the vibration on very low speed turns, so I took the AV out for a spin and got the same results. Seems to occur more on a left handed turn under 10MPH, and seems worse in Auto 4WD, hardly noticable in 2HI. I'm driving this week to get all list of gremlins in the truck before I bring it in for warranty work. Also, the heated seats don't seem to work.

shroutosaur :C:
? got my vehicle back yesterday with this write-up...

lubricated the steering stops and test drove in the parking lot. ?there is a definite noise in the left front when the vehicle is in motion with the wheels turned (not against the stops). ?contacted the technical assistance and spoke with Carmen Gemus. ?removed the left front crossmember and the left lower control arm bracket. ?heated the bolts and pushed them through the shims as instructed. ?installed the nuts and re-torqued the crossmember. ?test drove again. ?the noise is gone. ?OP's check OK.

? the vehicle does not make the noise anymore. ?the frontend seems to have a tighter/more stable feel to it now also. ?my hat's off to the dealer for squaring me away on this one. ;D ;D ;D
Same complaints--different fixes
Chiefs is the only one that makes sense as far as a rotational noise and vibration-when a differential goes bad it causes the axle to walk side to side, which can cause a feel in the steering wheel
The idler arm/.hub/lower control/ wouldn't seem to create a rotational noise

Did your Av, float or sway at highway speeds?
I've had a ongoing problem with myZ71
I looked at the control arm they fixed on yours and can see a gap on each side of the front control arm bushing
I could see where the addition of shims, would tighten up the suspension
did you get a copy of the repair order that lists the part # for the shims?
I too had a clunking at low speeds in the front end. But a different fix from what I've read so far in this thread. I have a Z66 with 15K and it was diagnosed as the steering shaft. The dealer disconnected the intermediate steering shaft, lubricated and so far (1000 miles) it has fixed the problem. Service advisor stated because of our warm weather here in Fl, the lubrication was breaking down.
my noise is not steering related. My truck can be going straight, and the noise happens. No vibration through steering wheel, just a thunking rattling noise between 5-30mph. Does not do it, if the engine is idling in park.... anyway, my truck is going in tomorrow to get it checked out... I will let you know if they find and fix it.
sorry Capecruis8der no part number to give you. i would take the truck in and mention the problem. they, or you , should be able to pull the TSB on it and get that info.